How do you combine insulation of an old roof with the installation of BIPV roofing?

A shared schedule reduces this risk.

This does not mean that every repair can be carried out exclusively from the outside. The scope depends on the layout of the house and the condition of the loft conversion. It is worth establishing it before ordering materials. This way, contractors do not have to make important decisions only once the interior has already been temporarily exposed.

Insulation limits the flow of heat through the building envelope. The cells use light to generate electricity. These are different tasks, even if they relate to the same roof slope. A solar roof does not exempt you from the requirements for insulation, and good insulation does not replace an analysis of energy yield. The benefits should be assessed separately and only then combined.

This distinction guards against the promise that a dark covering with cells will by itself improve the comfort of the loft. The temperature in the room depends on many elements, including glazing, airtightness and the ventilation of the house. The BIPV design should preserve the required layer build-up. Layers should not be removed for the sake of simpler panel fitting.

The condition, thickness and continuity of the material are important, as is its moisture content. Gaps or defects may occur at the eaves, the chimney and the junctions between roof slopes. The cause of the problem must be identified before another layer is added. Covering damp material is not the same as repairing the building envelope.

The selection of the new solution should take into account the structure and the moisture conditions. It is not enough to compare the declared thermal conductivity coefficients alone. Junctions, fixings and interruption points are also important. These are where a good material can lose part of its benefit if the design and execution do not ensure continuity.

It is also worth assessing the areas at the wall plate and the edges of the roof slopes. These are areas where continuity of insulation can be more difficult to achieve than in the middle of the roof.

Air from inside the building can carry moisture into cooler roof layers. Appropriate sealing of joints and penetrations is therefore required. The mere presence of a membrane in the build-up does not confirm that the whole is airtight. The junctions with walls, chimneys, windows and all services passing through the layers must be checked.

Replacing the roof together with PV increases the importance of coordinating installation routes. A new penetration should not damage the previously completed sealing layer. It is worth establishing responsibility for closing and accepting it. A few well-planned details can be of greater value than randomly adding further centimetres of insulation.

The arrangement specified for the selected BIPV system must be adopted. The inlet, outlet and continuity of the air flow path must remain unobstructed. The insulation should not accidentally block this space. The gap dimension should not be copied from another product, because different solutions have different requirements.

Good coordination makes it easier to achieve an aesthetically pleasing standing seam roof surface without sacrificing a correct build-up. Active and passive elements form an external whole, while the layers below perform their own tasks. This is how integration should be understood. It combines functions in the design but does not remove the principles of building physics.

The cost estimate should separately include repair work, insulation, sealing, substrate and covering with the electrical part. This allows offers to be compared for the same scope. It is worth planning acceptance of the layers before they are covered. Photographs of joints and penetrations will be useful for future inspections and changes to the home’s equipment.

Combining insulation with a BIPV roof can be a sensible renovation for years to come. The benefit is not limited to electricity generation. The house receives a renewed covering, tidied details and the opportunity to improve the building envelope. The condition, however, is a joint design that does not confuse the function of the cells with that of the insulation and does not omit hidden layers.

Manufacturers and brands of solar roofs include Electrotile, SoliTek, Wienerberger Wevolt, SunRoof, ML System, MDM NT (MyRoof), 3S Swiss Solar Solutions, SolRoof, LUMA Solar and Dyaqua.